Using a powershell script from Diafaan SMS Server is possible but there are a few caveats. In most situations it is probably easier to only use a C# script for the same functionality. The scripts are hard to debug and a tiny mistake means that the script does not work properly.

I'm not familiar to C#.
I have a powershell script that will perform a few tricks for me.

What I think i have to do is to create a Script Connector and put something in the OnMessageReceived so that when a list of phone numbers send a command to the SMS Modem, the message will be used as argument for the ps1 file.

I'm having problems setting up the script to invoke the ps1 file and argument.